For many years a standard masonry fireplace cavity whether of brick, stone, or other non-flammable materials usually required the standard dimensions of 36″ wide, 30″ high, 22″deep, and a rear dimension width of 24″. Early fireplaces had no “closure” doors and were “open” but would eventually accommodate a screen for fire prevention from flying sparks. Earlier colonial era fireplaces of two centuries ago included a one or two level height of stone or bricks on the hearth floor on each side called “hobs”. These hobs provided the several functions of a warming shelf, support to keep logs above the hearth “floor” and a more efficient way to confine and direct the draft of air more efficiently to the burning flame area by “closing-in” the space between the ends of the logs and the fireplace sides. Draft control consisted of minimal or no damper adjustment in order to control heat radiation, and the hobs helped direct draft air more effectively to the combustion flame area. In more modern days a front enclosure was employed utilizing hinged glass doors to allow easier replenishment of fuels for combustion. In recent years we have had a resurgent interest in obtaining better fireplace inserts, many looking like a smaller “Franklin-Type” design, (an iron-sided, heat-radiating, free-standing box with draft control doors).